Insulinomas, which are insulin over-producing tumors of the beta cells in the pancreas, are the most common cause of hypoglycemia related to HI. Insulinoma often manifests clinically as fasting hypoglycemia with discrete episodes of symptoms that indicate a shortage of glucose in the brain. If left untreated, potential problems include increased risk of neurological complications, recurrent seizures, brain damage or even death. Patients are generally categorized as having benign or malignant insulinomas, but insulinomas may be further characterized by disease severity. Surgical removal remains the preferred treatment choice, but medications to control hypoglycemia are often needed throughout the patient journey. Following surgery, patients may still require lifelong, episodic treatment to control hypoglycemic episodes. Up to 10% of insulinomas prove to be malignant and surgical resection alone may not be curative.